MinGW fix for kconfigbackend.cpp

[Brad King]

Hello,

The patch below does for mingw/signal.h what is already done for 
msvc/signal.h and is needed to build on MinGW.  Will someone with write 
access please commit the change?

Thanks,
-Brad

Index: win/include/mingw/signal.h
===================================================================
--- win/include/mingw/signal.h  (revision 508119)
+++ win/include/mingw/signal.h  (working copy)
@@ -36,7 +36,7 @@
  #define        SIGEMT  7       /* EMT instruction */
  /* #define     SIGFPE  8*/     /* floating point exception */
  #define        SIGKILL 9       /* kill (cannot be caught or ignored) */
-#define        SIGBUS  10      /* bus error */
+//#define      SIGBUS  10      /* bus error */ //only used in 
kconfigbackend.cpp but this signal.h is not complete
  #define        SIGSEGV 11      /* segmentation violation */
  #define        SIGSYS  12      /* bad argument to system call */
  #define        SIGPIPE 13      /* write on a pipe with no one to read 
it */